Responsible for the ongoing coronavirus disease 19 (COVID-19) pandemic, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infects host cells through binding of the viral spike protein (SARS-2-S) to the cell-surface receptor angiotensin-converting enzyme 2 (ACE2). Here we show that the high-density lipoprotein (HDL) scavenger receptor B type 1 (SR-B1) facilitates ACE2-dependent entry of SARS-CoV-2. We find that the S1 subunit of SARS-2-S binds to cholesterol and possibly to HDL components to enhance viral uptake in vitro. SR-B1 expression facilitates SARS-CoV-2 entry into ACE2-expressing cells by augmenting virus attachment. Blockade of the cholesterol-binding site on SARS-2-S1 with a monoclonal antibody, or treatment of cultured cells with pharmacological SR-B1 antagonists, inhibits HDL-enhanced SARS-CoV-2 infection. We further show that SR-B1 is coexpressed with ACE2 in human pulmonary tissue and in several extrapulmonary tissues. Our findings reveal that SR-B1 acts as a host factor that promotes SARS-CoV-2 entry and may help explain viral tropism, identify a possible molecular connection between COVID-19 and lipoprotein metabolism, and highlight SR-B1 as a potential therapeutic target to interfere with SARS-CoV-2 infection.

Background:Foxp3+ regulatory T (Treg) cells and M2 macrophages are associated with increased tumour progression. However, the interaction between Treg cells and M2 macrophages remains unclear.Methods:The expression of FoxP3 and CD163 was detected by immunohistochemistry in 65 cases of laryngeal squamous cell carcinoma (LSCC). In vitro, the generation of activated Treg (aTreg) cells and M2 macrophages by interactions with their precursor cells were analysed by flow cytometry and ELISA. In vivo, the antitumour effects were assessed by combined targeting aTreg cells and M2 macrophages, and intratumoural immunocytes were analysed by flow cytometry.Results:In LSCC tissue, accumulation of aTreg cells and M2 macrophages predicted a poor prognosis and were positively associated with each other. In vitro, aTreg cells were induced from CD4+CD25− T cells by cancer cell-activated M2-like macrophages. Consequently, these aTreg cells skewed the differentiation of monocytes towards an M2-like phenotype, thereby forming a positive-feedback loop. Combined targeting aTreg cells and M2 macrophages led to potent antitumour immunity in vivo.Conclusions:The positive-feedback loop between aTreg cells and M2 macrophages is essential to maintain or promote immunosuppression in the tumour microenvironment and may be a potential therapeutic target to inhibit tumour progression.

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Background Abnormalities in the KEPA1‐NRF2 pathway have a role in cancer progression, metastasis, and resistance to chemo‐ and radiotherapies. Persistent activation of NRF2 associates with poor prognosis across different cancer types. However, the beneficial therapeutic strategy to harness this pathway in cancer remains unclear. This study aimed to investigate the clinical outcome with immunotherapy in NFE2L2/KEAP1 mutant population. Materials and Methods We investigated the correlation between NFE2L2/KEAP1 mutations and tumor mutational burden (TMB) and programmed death‐ligand 1 (PD‐L1) expression status to identify the therapeutic vulnerability. For this purpose, relevance analysis with TMB value was performed in 9,040 patients with cancer, and relevance analysis with PD‐L1 expression was performed in 3,457 patients. The Memorial Sloan Kettering Cancer Center (MSKCC) database and real‐world evidence were used to assess the immunotherapy response in NFE2L2/KEAP1 mutant subsets. Results NFE2L2/KEAP1 mutations occurred in various cancers, and the highest mutation incidences occurred in lung squamous cell carcinoma (LUSC) at 19.16% (NFE2L2) and 10.31% (KEAP1). We confirmed that higher TMB value and PD‐L1 expression were associated with NFE2L2/KEAP1 mutations compared with wild‐type, especially in non‐small lung cancer. MSKCC database analysis showed the improved survival of patients with NFE2L2/KEAP1 mutant with immunotherapy compared with other treatments (median overall survival 22.52 VS 12.89, p = .0034). Real‐world evidence further confirmed the efficacy of immunotherapy in the mutant population. Conclusion Our study revealed that patients with NFE2L2/KEAP1 mutant could achieve improved outcomes from immunotherapy than the other treatments. These findings may broaden the application of immune checkpoint blockade to patients harboring NFE2L2/KEAP1 mutations. Implications for Practice NFE2L2/KEAP1 alterations occur frequently in multiple cancer types and are associated with poor prognosis; however, the efficacious strategy to inhibit this pathway in cancer is poorly understood. This study was designed to analyze the mutational characteristics of NFE2L2/KEAP1 alterations in 9,243 Chinese patients. The highest mutation incidences occurred in lung squamous cell carcinoma at 19.16% (NFE2L2) and 10.31% (KEAP1). Relevance analysis showed the NFE2L2/KEAP1 mutant subsets were associated with higher tumor mutational burden value and programmed death‐ligand 1 expression. Clinical data further confirmed NFE2L2/KEAP1 mutations correlate with improved outcome with immunotherapy. These findings suggest the clinical application of immunotherapy in the NFE2L2/KEAP1 mutant population.

Background: Mitochondrial dysfunction is considered to contribute to the development of age-related hearing loss (AHL). The regulation of mitochondrial function requires mitochondrial quality control, which includes mitophagy and dynamics. Dynamin-related Protein 1 (DRP-1) is believed to play a central role in this regulation. However, the underlying mechanism of DRP-1 in AHL remains unclear. Here, we examined whether the decline of DRP-1-dependent mitophagy contributes to the development of AHL. Methods: We induced cellular and cochlear senescence using hydrogen peroxide (H 2 O 2) and evaluated the level of senescence through senescence-associated β-galactosidase staining. We evaluated mitophagy levels via fluorescence imaging and Western Blotting of LC3II and P62. Mitochondrial function was assessed by ATP assay, mtDNA assay, and JC-1. Results: We found that both the expression of DRP-1 and the mitophagy level decreased in senescent cells and aged mice. DRP-1 overexpression in HEI-OC1 cells initiated mitophagy and preserved mitochondrial function when exposed to H 2 O 2 , while cells with DRP-1 silencing displayed otherwise. Moreover, inhibition of DRP-1 by Mdivi-1 blocked mitophagy and exacerbated hearing loss in aged C57BL/6 mice. Conclusion: These results indicated that DRP-1 initiated mitophagy, eliminated mitochondrial dysfunction, and may protect against oxidative stress-induced senescence. These results provide a potential therapeutic target for AHL.

The current dogma in ophthalmology and vision research presumes the intraocular environment to be sterile. However, recent evidence of intestinal bacterial translocation into the bloodstream and many other internal organs including the eyes, found in healthy and diseased animal models, suggests that the intraocular cavity may also be inhabited by a microbial community. Here, we tested intraocular samples from over 1000 human eyes. Using quantitative PCR, negative staining transmission electron microscopy, direct culture, and high-throughput sequencing technologies, we demonstrated the presence of intraocular bacteria. The possibility that the microbiome from these low-biomass communities could be a contamination from other tissues and reagents was carefully evaluated and excluded. We also provide preliminary evidence that a disease-specific microbial signature characterized the intraocular environment of patients with age-related macular degeneration and glaucoma, suggesting that either spontaneous or pathogenic bacterial translocation may be associated with these common sight-threatening conditions. Furthermore, we revealed the presence of an intraocular microbiome in normal eyes from non-human mammals and demonstrated that this varied across species (rat, rabbit, pig, and macaque) and was established after birth. These findings represent the first-ever evidence of intraocular microbiota in humans.

The Sr/Ca ratios in otoliths of silver Japanese eels Anguilla japonica in Pearl River, China, indicated that both sexes did not stay in brackish water and grew in fresh water from the glass eel stage until spawning migration. This did not support the hypothesis that females tended to distribute upstream and males might be restricted to estuaries. The back-calculated total length of males at glass eel stage was not significantly different from that of females, indicating that the hypothesis that small glass eels became males and larger ones became females may not be true. The mean ( ..) age and total length of males at migration were 6·4 1·6 years and 48·3 4·5 cm, which were significantly smaller than for females, 8·3 1·6 years and 61·4 4·1 cm. The age of migration was related inversely to growth rate for both sexes. Growth parameters of the von Bertalanffy growth equation were K=0·21 cm year 1 , L`=55·7 cm and t o = 0·55 year for males and K=0·14 cm year 1 , L`=77·5 cm and t o = 0·60 year for females. The difference in asymptotic length (L`) between males and females may be because females postpone migration to achieve larger size for maximizing reproductive success. 2000 The Fisheries Society of the British Isles